Eco-Driving Of Vehicle Platoons In Cooperative Vehicle-Infrastructure System At Signalized Intersections

When the fuel are fewer and traffic emission issues are becoming increasingly serious in recent years,the energy conservation and emission reduction has become one of the strategic objectives of transportation industry in China.As an advanced technology of Intelligent Traffic System(ITS),the cooperative vehicle-infrastructure system can help drivers implement eco-driving based on real-time traffic environment.This means that the technology can effectively reduce the fuel consumption and emissions of vehicles.Hence,the researchers has paid more attention on the cooperative vehicle-infrastructure system.Meanwhile,the signalized intersection is a key area because it's an important node of urban road traffic.But most existing studies on the eco-driving in cooperative vehicle-infrastructure system at signalized intersections aimed at single vehicles.The phenomenon that the vehicles always form the vehicle platoons at signalized intersections were neglected.Furthermore,researchers always ignored the essence of fuel consumption.When the eco-driving model is developed,to reduce the number of stops is generally considered to save fuels and reduce emission.Thus,the fuel-saving effects of the eco-driving were difficult to be controlled and quantified.In this context,this thesis presented an eco-driving model of vehicle platoons in cooperative vehicle-infrastructure system at signalized intersections.The model was established based on the eco-driving in cooperative vehicle-infrastructure system and the micro fuel consumption estimation model.Firstly,the method to distinguish platoon in the cooperative vehicle-infrastructure system was designed.The main parameters were the headways and instantaneous speed.Then,considering the signal status at a signalized intersection and the running conditions of the downstream vehicle,the running time ranges of the vehicle platoon passing through the intersection without a stop were determined.Next,the running trajectories of the head vehicle and the following vehicles in the vehicle platoon were analyzed in order to obtain the criteria to provide guidance and the ranges of the guidance driving trajectories of the vehicle platoons.Finally,using the genetic algorithm,the eco-driving trajectories of the vehicle platoons could be selected.The objective function was formulated based on the running time and fuel consumption,which was estimated by using the micro fuel consumption estimation model.The eco-driving model of vehicle platoons in cooperative vehicle-infrastructure system at signalized intersections was established.The model was applied in a case study using VISSIM simulation platform and Python programing.The running conditions and fuel consumptions of vehicle platoons were estimated and comparative analysis has been conducted.The results show that the model could effectively reduce the fuel consumptions of the vehicle platoon.The model could also reduce the frequencies of sharp acceleration and deceleration,which assist the vehicle platoon to pass through the signalized intersection more smoothly.The effectiveness of the eco-driving model of vehicle platoons was verified.